Nuclear-Medizin最新文献

In 175 patients the results of combined isotope studies i. e. inhalation and perfusion scintigraphy were compared with those of chest x-ray. The absorbed radiation dose due to the inhalation study calculated for whole body was 3 mrad/500 muCi, lungs 380 mrad/500 muCi, ovaries 0.3 mrad/500 muCi and testes 0.03 mrad/500 muCi. In 44 of our cases the isotope studies suggested the presence of a vascular occlusion, not detectable on the x-ray film in 36 cases. In the remaining 8 cases the inhalation study was found to add to the precision of the diagnosis. In nearly all other cases it was not found to have any diagnostic value.

About 100 patients with hyperthyroidism and diffuse goiter (gland weight not more than 60 g) were treated with an individually calculated dose of 125-Iodine. After a follow-up time between 1.5 and 2 years there are the following results: 82% of the patients are euthyroid and 18% are still hyperthyroid. Relapse rate was 10%. More than 30% of the residual or relapse hyperfunctions were T3 toxicosis. The status of 125-Iodine in the treatment of thyrotoxicosis is discussed with regard to the necessity of a "destructive" therapy in the major part of the patients. Published results of 125-Iodine therapy are summarized.

Knowledge of the regional ventilation/perfusion ratio is of great interest for the diagnosis and therapy of disorders of pulmonary function. By injecting intravenously a bolus of Xe-133 during breathholding and by recording the influx of activity into the lung with a scintillation camera and analogue tape storage, the regional perfusion of the lungs can be determined, using the count-rate increase per unit time. Once the maximum count-rate is reached the patient is allowed to breathe normally. The slope of the count-rate decrease over the lungs is a measure of ventilation. The regional ventilation/perfusion ratio is calculated by dividing these two indices. Regional disturbances of the ratio are the most frequent cause of hypoxia. The demonstration of such disturbances are therefore of significance in the diagnosis and therapeutic control of pulmonary diseases.

The stability of tin-phytate solution stored at room temperature has been studied. It was found that there is a pronounced increase in the rate of degradation of this complex, both temperature and phase change contributing to the enhanced rate of decomposition. The kidney uptake which is occasionally observed clinically with an aged tin-phytate complex labelled with 99mTc is probably due to an intermediate product which subsequently breaks down on further storage. Lyophilized tin-phytate complex 'kits' have a longer shelf life than the aqueous complex.

14C-labelled Diazepam is applied i.v. in a single dose to pregnant rabbits and in three repeated doses to lactating rabbits. The distribution patterns of the radioactivity in the mother animal and in the fetus resp. in the sucklings are investigated at different intervals post inj. within a range of 10 to 120 minutes for the pregnant and at 8 hours after last injection for the lactating animals. With regard to its metabolic properties it is still admissible to identify the recorded radioactivity with the intact pharmaceutical to large extent for the intervals used in the experiments. The compound is distributed rapidly within the maternal organism and is excreted preferentially by the liver. Compared to blood level a considerable 14C-enrichment is obvious in the brain during the total time of investigation, which seem to be of special interest for the clinical use of the diazepam. An organotropism to the ovary is indicated by the patterns of radioactivity. A rapid diaplacental passage can also be shown, but the 14C-concentrations in blood and organ tissues of the fetus are generally found to be lower than those of the maternal organ tissues. Thus, the 14C-concentration in the fetal brain is equal to 1/3 of that of the maternal brain. Due to the mammoglandular passage the 14C-concentrations in the sucklings are reaching a maximum of one half of the values in the maternal organs.

Brain scans with 99mTc pertechnetate were compared with scans made after administration of 111Indium bleomycin in 38 patients scanned on 41 occasions. They gave similar results in 34 pairs of examinations, including cases in which both failed to detect the tumour. In seven cases, the two agents differed. In two of these bleomycin distinguished residual tumour from the effects of craniotomy more clearly than did pertechnetate; in three bleomycin apparently detected tumour not seen with pertechnetate, and in two the differences may have been due to technical factors, or are unexplained.

In the course of coronary angiographies the blood flow of the right and left coronary artery was determined by the 133Xe lavage method in 89 patients with coronary heart disease. There was a statistically significant difference between the flow values of the LCA and RCA, while there was none between the blood flow values of blue- and white-collar workers suffering from coronary artery disease. Also a significantly better blood circulation of the right as well as of the left coronary artery was found in female employees in comparison to male employees.

The kinetic of 51Cr-labelled autologeous and heterologeous thrombocytes was studied in 12 healthy volunteers. The mean recovery value was 63% (SX = +/- 15%). The survival times (t50% and t10%) were determined as 94 hrs. (SX = +/- 11 hrs.) and as 202 hrs. (SX = +/- 13 hrs.) respectively. The "excess counts" over spleen and liver were measured and the spleen to liver ratio calculated. In every parameter investigated no significant difference between autologeous and heterologeous labelled thrombocytes could be found. The "excess counts" over spleen and liver were calculated on the basis of the radioactivity of blood and of the heart surface area. The values obtained from the blood radioactivity calculations showed significant lower variation coefficients than the corresponding values derived from the heart measurements.

Twenty patients were tested with an isotope profile method for the detection of venous thrombosis in the leg. 131I-MAA was introduced into the dorsal vein of the foot. The results of the test agreed with the results of phlebography. The authors stress the simplicity and accuracy of the above method.

In 68 euthyroid patients undergoing 131I thyroid function tests the thyroidal, urinary and plasma protein-bound radioactivity has been serially measured for 14 days. The patients were subdivided in controls and 9 groups treated with potassium iodide, carbimazole, potassium perchlorate and TSH, singly or in combination. The aim was to devise a treatment scheme for accelerating the release of iodine from the thyroid and the elimination from the body in cases of accidental radioiodine poisoning if the patient is seen after the radioiodine has already been taken up by the gland. All treatment schedules were effective, but TSH injections gave the best results, especially if combined with carbimazole and potassium perchlorate. This combination is the treatment of choice under these circumstances.